Treatment of Obstructive Sleep Apnea (OSA) with Continuous Positive Airway Pressure (CPAP) flow generator systems involves the continuous delivery of a breathable gas (generally air) pressurised above atmospheric pressure to a patient's airways via a conduit and a mask. CPAP pressures of 4 cm H.sub.2 O to 22 cm H.sub.2 O are typically used for treatment of OSA, depending on patient requirements. Treatment pressures for assisted ventilation can range of up to 32 cm H.sub.2 O and beyond, again depending on patient requirements.
For either the treatment of OSA or the application of assisted ventilation or similar, the pressure of the gas delivered to patients can be constant level, bi-level (in synchronism with patient infpiration) or auto setting in level. Throughout the specification reference to CPAP is intended to incorporate a reference to any one of, or combinations of, these forms of pressurised gas supply.
It is difficult to administer substances such as medicines to patients undergoing CPAP treatment without interrupting the treatment by removing the gas supply mask.
It is an object of the present invention to ameliorate the above disadvantage.